1. Field of the Invention
This invention relates to a method for preparing poly(alkylene carbonate) monoahls and/or polyahls useful as surfactants or functional fluids and to novel monoahls and/or polyahls based on alkyl or aryl mercaptans or their alkoxylate derivatives. This invention also relates to poly(alkylene carbonate) polyahls.
2. Description of the Background
Poly(alkylene carbonate) polyahls are randomized polymers containing a plurality of carbonate moieties and a plurality of active hydrogen moieties and, optionally, other moieties such as di- and higher polyalkyleneoxy units. An alkylene carbonate moiety is a repeating unit comprising an alkylene group bound to a carbonate moiety. Poly(alkylene carbonate) polyahls are known to be useful as surfactants.
Surfactants are compounds that reduce the surface tension when dissolved in water or water solutions, or which reduce the interfacial tension between two liquids, or between a liquid and a solid (see, for example, Nonionic Surfactants edited by M. J. Schick, Marcel Dekker, Inc., New York, 1967). Functional fluids are polyglycol-based fluids such as lubricants, hydraulic fluids, brake fluids, and compressor fluids (see, for example, Kirk-Othmer 12: 719; ibidem., 18: 633).
A variety of surfactants have been prepared by Langdon and described in a series of patents. U.S. Pat. No. 4,072,704 describes the coupling of polyethylene glycols and polypropylene glycols with either dialkyl carbonates or formaldehyde to give materials with surface active properties. In U.S. Pat. No. 4,353,834 it is described how long chain amides or sulfonamides have been coupled with hydrophilic polyglycols using dialkyl carbonates or esters of dicarboxylic acids to give materials with surface active properties. This work was extended in U.S. Pat. No. 4,504,418 to include polyoxyalkylene polymers and monofunctional aliphatic, aromatic or aliphatic-aromatic alcohols coupled by alkyl carbonates or esters of dicarboxylic acids to give materials with surface active properties.
U.S. Pat. No. 4,330,481 to Timberlake et al. describes the preparation of surfactants by reacting alcohols or alcohol ethoxylates with ethylene carbonate. These products are then further reacted with ethylene oxide to produce different surface active materials as reported in U.S. Pat. No. 4,415,502. The preparation of surfactants and functional fluids by reacting alcohols, phenols or carboxylic acids (or their alkoxylated derivatives) with alkylene carbonates or alkylene oxides and carbon dioxide is described in U.S. Pat. No. 4,488,982 to Cuscurida.
U.S. Pat. No. 4,382,014 to Sakai et al. describes the preparation of surface active materials by reacting alcohols, carboxylic acids or primary or secondary amines containing four or more carbon atoms or substituted phenols with alkylene carbonates in the presence of an ate-complex of a metal of Group II, III or IV of the Periodic Table having at least two alkoxy groups.
Low molecular weight polyoxyethylene glycol monomethyl ethyls have been coupled using phosgene or alkyl carbonates to give materials useful in formulating brake fluids and as synthetic lubricants, as disclosed in U.S. Pat. No. 3,632,828. The coupling of monofunctional alcohols, phenols or their ethoxylated derivates using diphenyl carbonate to give surfactants is disclosed in U.S. Pat. No. 3,332,980.
Some poly(alkylene carbonate) polyahl nonionic surfactants of the general type produced by the method of the invention have been made by various procedures, including reacting alcohols with cyclic alkylene carbonates and reacting alcohols with alkylene oxides and carbon dioxide. However, before the present invention poly(alkylene ether carbonate) polyahls have never been used as the carbonate source in preparing carbonate-containing surfactants.
Moreover, carbonate-containing surfactants based on alkyl or aryl mercaptans or their alkoxylate derivatives, which comprise a further part of this invention, are novel.